If you were to sit a hot cup of water out side it would frezze faster
The lens equation gives d relation between focal length, object distance n image distance.
1/f = 1/v + 1/u
seldon
Let's calculate the average acceleration. It is the rate of changing speeds. Hence, we need to calculate the difference of speeds. 10-6=4 m/s. The rate is now
.
In general, the formula for the mean acceleration between two times 1 and 2 is given by:
where v1 and v2 are the speeds at the respective points and T is the time interval between them.
Answer:
the human brain is responsible for involuntary activities, such as regulating heartbeat, breathing, and blinking. Although the brain controls both voluntary and involuntary activities, different regions of the brain are devoted to each type of task.
Both involuntary and voluntary actions are controlled by the same parts of the brain. Hindbrain and midbrain control involuntary actions like salivation, vomiting, etc. All the body's voluntary actions are controlled by the motor cortex in the frontal lobe of the cerebrum.
Explanation:
Answer:
μk = 0.26885
Explanation:
Conceptual analysis
We apply Newton's second law:
∑Fx = m*a (Formula 1)
∑F : algebraic sum of the forces in Newton (N)
m : mass in kilograms (kg)
a : acceleration in meters over second square (m/s²)
Data:
a= -0.9 m/s²,
g = 9.81 m/s² : acceleration due to gravity
W= 75 N : Block weight
W= m*g
m = W/g = 75/9.8= 7.65 kg : Block mass
Friction force : Ff
Ff= μk*N
μk: coefficient of kinetic friction
N : Normal force (N)
Problem development
We apply the formula (1)
∑Fy = m*ay , ay=0
N-W-25 = 0
N = 75
+25
N= 100N
∑Fx = m*ax
20-Ff= m*ax
20-μk*100
= 7.65*(-0.90 )
20+7.65*(0.90) = μk*100
μk = ( 20+7.65*(0.90)) / (100)
μk = 0.26885
